Abstract: In order to solve the problems of short service life of ϕ8.0 m×3.2 m semi-autogenous mill unloading tank and affecting the operation rate of equipment in Yuxi Dahongshan Mining Industry，aiming at the serious non-uniform wear phenomenon existing in the radial unloading tank of semi-autogenous mill， a comprehensive research of field investigation，wear causes analysis，material sliding dynamics modeling and industrial application verification is carried out.The results show that the structural defects of the radial discharge tank are the root cause of the poor discharge，the repeated reflux erosion of the slurry and the local abnormal wear.By transforming the radial unloading tank into a curved design，the service life of the new un⁃ loading tank is extended from 486 d to 1 200 d，the average hourly processing capacity of the mill is in⁃ creased by 5.22%，and the unit power consumption per ton of ore is reduced by 9.51%，with remarkable economic benefits.

Key words: unloading tank, curve lifting bar, wear causes, critical curve